کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
231160 | 1427414 | 2012 | 6 صفحه PDF | دانلود رایگان |

Few-layer graphene (FG) is produced in supercritical N,N-dimethylformamide (DMF) using expandable graphite (EG) as starting material in less than 15 min. Monolayer graphene is produced by exfoliation of FG in supercritical DMF. The samples were characterized by atomic force microscopy (AFM), X-ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), and Raman spectroscopy. AFM result reveals that the average thickness of FG is about 3 nm and monolayer graphene is about 1.2 nm. Raman result indicates that the ID/IG of FG is 0.3, which proves a small proportion of defects in it. Moreover, we have studied the effect of process parameters on the yield of FG. Results show that a yield of 7 wt% can be obtained at an optimum condition (with concentration being 2 mg/ml, temperature being 673 K, and volume ratio being 0.67). Besides, the temperature of FG formation is very low (473 K). Finally, these results show that EG is an excellent precursor for the fabrication of FG and monolayer graphene.
Figure optionsDownload as PowerPoint slideHighlights
► Exfoliation of expandable graphite in supercritical N,N-dimethylformamide is proposed.
► Few-layer graphene is produced by this process.
► Single-layer graphene about 1.2 nm is obtained by treating Few-layer graphene.
► Concentration, temperature, volume ratio affect the yield of Few-layer graphene.
Journal: The Journal of Supercritical Fluids - Volume 63, March 2012, Pages 99–104